Spotify is testing a native voice activation feature
This intriguing snippet of info has been unearthed by app researcher Jane Manchun Wong, who also unraveled that the hotword to enable the assistant will be "Hey Spotify". However, you will only be able to use it when the app is open as revealed by the hinted Android app permissions that the feature would require. The voice-activation feature will be residing in a new Voice submenu in Spotify's settings.
This could come in useful in certain very specific use-case scenarios. For example, imagine you're driving down the road with Spotify already open on your phone, but manually searching for a specific artist would be hazardous - this is when you might make use of the "Hey, Spotify" hotword and keep your hands on the wheel. You can already use the Google Assistant and Siri to actively search Spotify for your favorite artists and songs, and those two work great even if the app is not actively open, but a native solution wouldn't be bad.
It seems unlikely that Spotify's voice commands will provide the rich feedback that complex voice assistants like Google Assistant, Siri, and Alexa provide, but we'd love to be surprised.
Currently, we don't know when this feature would come along, and we are not even sure if it will arrive at all.